Under the microscope: a first introduction to soil life
A drop of a properly prepared sample reveals soil and compost life. Bacteria, fungal hyphae, protozoa and nematodes participate in decomposition and nutrient cycling.
A living world in a drop
Among particles and residues we can distinguish cells, fine hyphae and moving organisms. The Soil Food Web School uses microscopy to examine communities in soil and application materials, and offers educational resources on microscope use.
Equipment and magnification
A biological light microscope with 4×, 10× and 40× objectives and a 10× eyepiece provides total magnifications of 40×, 100× and 400×. Lower magnification gives a broader overview; higher magnification reveals detail. Appropriate focus and lighting help distinguish forms.
What we look for
Bacteria appear as very small cells; fungi form characteristic threadlike hyphae. Decomposers in both groups feed other food web organisms.
Protozoa include flagellates, amoebae and ciliates. Movement helps distinguish them: flagella, pseudopodia and cilia respectively. Many consume bacteria and release nutrients.
Nematodes are microscopic wormlike animals. Different groups eat bacteria, fungi, other organisms or plant roots. Identifying feeding groups is more informative than simply recording presence.
From sampling to records
We record sample origin, date, location, compost batch stage or field application stage. Consistent preparation and multiple fields of view support comparisons. Images and videos record magnification and, where calibrated, scale, allowing later review and comparisons over time.
Images need measurement
Microscopy assesses group presence and abundance and, with an appropriate protocol, permits quantitative estimates. These require known preparation, dilution and field size. Species identification may need additional methods. The School combines observation with identification and interpretation practice.
Microscopy answers questions about the observed community. Other measurements assess infiltration, structure, pH or nutrient availability. Kathleen Groppe’s 2026 School article explains how these complement one another. Biology, conditions and plant health together give a fuller picture.
Our field work
We examine compost piles, extracts and teas and develop an image and video archive for research and education.